Control system



CONTROL SYSTEM Filed Sept. 26, 1963 3 Sheets-Sheet 1 Jan. 25, 1966 w. R.M DURMONT 3,230,713

CONTROL SYSTEM Filed Sept. 26, 1963 3 Sheets-Sheet 2 73-\ '65 a 67 e9 -c1811- 1966 w. R. MODURMONT CONTROL SYSTEM 3 Sheets-Sheet 3 Filed Sept.26, 1963 United States Patent 0 3,230,713 CONTROL SYSTEM Walter R.McDurmont, Birmingham, Ala., assignor to Anderson Electric Corporation,Leeds, Ala., a corpora= tion of Alabama Filed Sept. 26, 1963, Ser. No.311,787 9 Claims. (Cl. 6052) This invention relates to a control systemfor compression crimping tools and more particularly to a control systemfor fluid-pressure-operated crimping tools adapted to crimp connectorsonto cables, electrical conductors, and the like.

Among the several objects of this invention may be noted the provisionof a control for compression crimping tools which permits the connectoror workpiece, rior to being crimped, to be held by the tool with aminimum gripping pressure; the provision of a crimping apparatusincluding a fluid-pressure-operated crimping tool in which the crimpingdies may be inched or moved together until a predetermined minimumgripping or holding pressure is exerted on a connector, the minimumgripping pressure once reached thereafter being maintained after thesupply of pressurized fluid to the tool is discontinued; the provisionof such crimping apparatus in which the crimping dies, subsequent to thecrimping of the connector, are maintained in firm contact with thecrimped connector with a minimum gripping pressure until the operatordesires to remove the tool therefrom; the provision of a control forcrimping tools which is useful to control the operation of the tool whenlocated in a position remote from a source of pressurized fluid supply;the provision of a control of the class described which can beconveniently operated by one hand and which permits the crimping tool tobe hotst=ick mounted; the provision of a control for compressioncrimping tOOls which enables the operator to stop the movement of thecrimping dies :at any desired opening or position; the provision of suchcontrols which permit the operator to position the tool initially togrip the connector or workpiece to be crimped so that the tool may beused as a holding device for the connector, thereby reducing the timerequired for installation of crimped connectors and to overcome jobawkwardness in forming crimped connections on overhead conductors; theprovision of crimping apparatus including such controls which may beconveniently used in the field and which is compact, self-contained,easily isolated from ground, and in which the crimping tool may beoperated from a position remote from air or electrically drivenhydraulic pumps; and the provision of crimping apparatus which isreliable in operation, light in weight, and simple and economical inconstruction. Other objects and features will be in part obvious and inpart pointed out hereinafter.

Briefly, my invention comprises a control for a fluidpressure-operatedcrimping tool which may be actuated by fluid under pressure from asupply source. The control is interconnected by a fluid line between thesupply source and the tool and has a fluid passage with 21 normallyclosed check valve positioned therein. This valve opens to supply fluidto the tool when fluid under pressure is supplied from the source. Thecontrol also includes an auxiliary or second check valve which will openwhen the pressure in the tool and downstream from the first check valveexceeds a predetermined value, which effects the bleed off of pressurefrom the tool and then automatically recloses and maintainssubstantially the predetermined value of pressure in said tool.Preferably the control also includes means, such as an electric switchor a pneumatic valve, which functions selectively to actuate anddeactuate a hydraulic pump or other convenient "ice supply source forpressurized fluid, and another means (preferably manually operable) forselectively opening the auxiliary valve to vent or release the fluidpressure at the tool and to permit its return to the supply source.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated,

FIG. 1 is a schematic of an embodiment of crimping apparatus of thepresent invention, an electrical power source being provided;

FIG. 2 is a section of the control of the crimping apparatus shown inFIG. 1;

FIG. 2A is a section taken on line 2A2A of FIG. 2 and showing a certaincheck valve in an open position;

FIG. 3 is a schematic of another embodiment of crimping apparatus of thepresent invention in which compressed air is utilized as the powersource;

FIG. 4 is a partial section taken on line 4-4 of FIG. 5; and

FIG. 5 is a bottom plan of the control of the crimping apparatus of FIG.3.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

Referring to FIGS. 1 and 2 of the drawings, a fluidpressure-operat-edcrimping tool of crimping apparatus of one embodiment of this inventionis generally indicated at reference character T. Tool T may, forexample, be of the type shown and described in my coassigned copendingUS. patent application Serial No. 115,625, filed June 8, 1961, nowPatent No. 3,154,981 granted November 3, 1964 which includes, ahydraulic ram type fluid motor 1 operatively connected to movable dies3. Upon actuation of motor 1, dies 3 converge uopn a workpiece such asan electrical connector (not shown) positioned between movable dies 3and a fixed die 5. A control C of the present invention isinterconnected by a hydraulic fluid line 7 between a hydraulic pump Pand tool T. Pump P, interconnected by a hydraulic fluid line 9 to areservoir R, serves as a supply source for pressurized fluid. Preferablythis supply source includes a pressure relief valve V which isautomatically actuated when a preselected high (e.g., 10,060 psi.)pressure in line 7 is exceeded to thereby return fluid via a return line11 to reservoir R. This pressurized fluid supply source also includes anelectric motor M driving pump P and a suitable unloading valve (notshown) for the system which, upon deactuation or" the pump,automatically opens, permitting hydraulic fluid to return to reservoir Rfrom line 7 thereby reducing the pressure in line 7 to atmospheric. Suchpressurized hydraulic fluid sources are available commercially, one suchtype being a light-wenght, compact port-able unit obtainable under thetrade designation #1729 from Greenlee Tool Co. of Rockford, Illinois.This crimping apparatus may be conveniently carried by the lineman withthe pump motor M being powered by a self-contained chargeable battery B.If desired, the apparatus may be electrically powered from the batteryof a utility service vehicle or any other convenient source of A.C. orDC. power.

The electrical power source B is electrically interconnected to motor Mby means of electrical lines L1 and L2, the latter including a cable 13connected to control C. Cable 13 is strain-secured to the control body Cby means of a compression bushing 15 threaded into the end of a bore 17having an insulated internal sleeve 19. A conventional spring-biasedopen single-pole singlethrow switch 21 is mounted at the other end ofbore 17 having its contacts serially connected in line L2. Switch 21 hasa plunger type actuator 23 positioned for operation by actuating cam 25pivoted on the control body tion by an actuating cam 25 within a slot 29thereof. An L- shaped trigger 31, having a projection 33 riding on cam25, is mounted for pivotal movement about a pin 35 and within slot 29.The outer leg of trigger 31 is concavely recessed at 37 to accommodatethe finger of a lineman.

Extending through control body C is a main fluid passage 39 having aninlet 41 and an outlet 43. A coupling 45 on fluid line 7 terminates in anipple 47 threaded Within inlet 41. Crimping tool T is interconnected tooutlet 43 by a threaded nipple 49. Mounted in fluid passage 39 is acheck valve including a ball 51, a spring 53 biasing ball 51 to a closedposition against a seat 55, and a retainer 57 which holds spring 53 inposition. This normally closed check valve prevents the return of fluidfrom tool T through fluid passage 39 and opens at a relatively lowpressure (e.g., about 100 p.s.i.) to supply pressurized hydraulic fluidto tool T.

A bypass passage 59, constituting a bleed for tool T, communicates at 61with outlet 43 and at 63 with inlet 41. An auxiliary valve constitutinga second check valve is provided in this bypass 59. This valve includesa check ball 65 carried in a concave end portion of a valve stem 67which has a reduced shank portion, and a spring 69 positioned around themidportion of the shank portion and having one end bearing against theinner surface of a bushing 71, thereby biasing the valve stem 67 so thatvalve check ball 65 is biased against a valve seat 73.

' This normally closed check valve prevents the release of hydraulicfluid from tool T as long as fluid pressure in bypass 59 does not exceedthe predetermined but relatively low pressure (e.g., l200 p.s.i.) asdetermined by the biasing force of spring 69.

The outer end of the valve stem shank is slidable within the bore ofbushing 71 and may be retracted to open this auxiliary valve by manualmovement of a toggle trip 75 pin-connected at 77 to the shank endprotruding from the control body C. As corners 79 of the portion oftoggle trip 75 which engage the surface of the body of control C arearcuate and spring 69 biases valve stem 67 inwardly, trip 75 willautomatically return to its dashed-line position (FIG. 2A) when manualpressure is discontinued.

Operation is as follows:

A workpiece, such as a connector to be crimp-connected to a cable or thelike, is positioned within the jaws of crimping tool T and between thecrimping dies 3 and 5. Trigger 3]. is initially momentarily depressedone or more times, thereby forcing fluid under pressure by normallyclosed check valve ball 51 and causing initial converging movement ofdies 3 against the surfaces of the Workpiece to be crimped. Upon eachrelease of trigger 31 the fluid pressure in line 7 (i.e., upstream fromthis check valve) is released or vented by the unloading valve (notshown) which returns the fluid in line 7 to the reservoir each time pumpmotor M stops. The fluid pressure in tool T (i.e., downstream from valveball 51), however, can only be released by opening of the auxiliary orsecond check valve. When the fluid pressure downstream from check valveball 51 exceeds a predetermined value, i.e., the fluid pressure at toolT is more than 100 p.s.i. (assuming this is the biasing force of spring69 against ball 65), ball 65 will move away from its seat and bleedpressurized fluid from tool T until the tool pressure drops to thispredetermined value. Thus, the pressure in tool T is maintained at thisreduced pressure, thereby causing the dies 3 and to efifect a light butfirm gripping pressure on said connector. The lineman operating thiscrimping apparatus may then move the connector to the desired positionengaging a cable or electrical conductor.

Trigger 31 is then again depressed and held depressed, causingpressurized fluid to be supplied through line 7 and passage 39 past thefirst check valve ball 51 to tool T to eifect crimping of the connector.During this operation, and during any period when trigger 31 is helddepressed, the pressure upstream and downstream of the check valve ball51 is equalized and auxiliary check valve 65 will be held open by thehydraulic pressure overcoming the biasing action of spring 69. If, atany time prior to completion of the crimping operation, trigger 31 isreleased, the fluid pressure in line 7 will drop due to operation of theunloading valve (not shown) associated with pump P, and the pressure intool T will also drop, but not below the 100 p.s.i. predetermined valuesince the check valve 65 closes at this pressure by biasing ac tion ofspring 69 thereby causing the tool dies to continue to grip theconnector. When the fluid pressure at tool T reaches the preselectedhigh (assumed, for example, to be 10,000 p.s.i.) value, valve V willopen. If trigger 31 is thereafter held in the depressed position,hydraulic fluid will simply be returned to reservoir R via line 11 andtool T will not exert any increased pressure on the already fullycrimped connection. This operation of valve V will indicate thecompletion of the crimping operation to the lineman, not only by theaudible sound of its operation, but by the sudden relaxation of thefluid pressure in line 7.

Trigger 31 is then released by the lineman and this action causesdeenergization of pump P and venting of the line 7 to atmosphericpressure. Auxiliary valve ball 65 will remain open against therelatively light biasing action of spring 69, thereby bleeding thehighly pressurized fluid from tool T via passage 59 to line 7 and thenceto reservoir R. The pressure in tool T will rapidly drop until itreaches the 100 p.s.i. predetermined value, whereupon this auxiliaryvalve closes, maintaining this reduced pressure and a continued lightbut firm gripping action of the tool dies on the crimped connection. Toremove the tool from the crimped connection, the lineman simply movestoggle trip 75 from its dashed to its solid-line position (FIG. 2A)which overcomes the bias of spring 69 moving ball 65 away from its seat73, thereby bleeding the tool T. As the dies 3 are lightly biased to anopen position, the tool'can then be conveniently disengaged from thecrimped connection for a subsequent operation. As the crimping toolcannot be removed from the connector unless toggle trip 75 is manuallyactuated, inadvertent partial crimping is avoided.

It is to be noted that control C is easily gripped by only one hand,with toggle trip 75 and trigger 31 both being easily accessible to thelineman. This allows the lineman to perform gripping and crimpingoperations sequentially. and repetitively while having one hand free toposition connectors in the jaws of the tool, or for support.

Crimping tool T is easily removed from control C by unthreading nipple49. A hot-stick extension (not shown) may be easily inserted betweencontrol C and tool T in a minimum time. Such an extension isparticularly useful for overhead Work such as making a tap connection toa primary circuit or conductor.

Referring to FIGS. 3, 4 and S, an alternate embodiment is shown in whichpump P in the fluid system is driven by an air motor AM instead of bythe electric motor M employed in the first embodiment described above.This second embodiment is also particularly adapted for use with utilityservice vehicles which are normally equipped with air compressors,constituting an air source for the operation of the motor AM. The fluidsystem in the FIGS. 3-5 embodiment is identical to that of FIGS. 1 and2, and like references are employed for the fluid system.

An air compressor, illustrated diagrammatically at 81, delivers air viaan air line 82 to a control valve 83 which controls the flow of air toair motor AM. A pilot air control valve, generally designated 85,positioned in control C, controls the opening and closing of valve 83.Small-diameter, flexible, pilot control lines 87 and 89 interconnectpilot control valve and control valve 83.

Pilot line 87 communicates with air line 82 and leads to an inletchamber 91 in control C.

Pilot control valve 85 includes a valve body93 having a central bore 95in which a valve stem '97 is slidable. Heads 99 and 101 areprovided onvalve stem 97 and are adapted to seat against respective seats 103 and105. A spring 107 biases valve head 99 into seating engagement with seat103. An outlet port 109 communicates with bore 95 and an outlet passage111. A trigger 113 is pivoted at 115 on the body of control C. Mountedon trigger 113 is adownward projection 117 contactingvalve head 101.Manual depression of trigger 113 moves valve head 99 against the bias ofspring 107, thereby seating valve head 101 and unseating valve head 99.Air will then flow from control line 87,through inlet chamber 91, bore95, outlet port 109, air passage 111, and pilot control line 89 tocontrol valve 83, thereby opening it to supply compressed air to motor'AM for driving pump P. Release of 'trigger 113 effects reseating ofvalve head 99 under him of spring 107 to stop the flow of air throughpilot valve 85 to valve 83 which then closes to stop air motor AM. Theoperation of the embodiment of FIGS. 3-5 in effecting the crimpingoperation is identical to the operation of the embodiment of FIGS. 1 and2, the pump P being operated by a pneumatic motor and a pneumatic valve,rather than by an electric motor and switch.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. A control for a fluid-pressure-operated crimping tool adapted to beactuated by fluid under pressure from a supply source including areservoir and a pump, a fluid line interconnecting said control and saidsupply source, said control comprising a first fluid passage and anormally closed check valve in said passage adapted to open and supplyfluid to said tool when fluid under pressure is supplied from saidsource, said control further including a second fluid passage bypassingthe check valve, an auxiliary valve in the bypass passage, means biasingthe auxiliary valve closed against a predetermined fluid pressuredownstream from the check valve, the auxiliary valve being adapted toopen when the pressure in the tool and downstream from the check valveexceeds the predetermined pressure, the means biasing the auxiliaryvalve closed automatically reclosing the auxiliary valve when the fluidpressure in the tool and downstream from the check valve falls below thepredetermined pressure whereby the tool remains under substantially saidpredetermined fluid pressure after the pressure in the fluid line fallsbelow the predetermined value, and means for selectively relieving thefluid pressure in the bypass passage between the auxiliary valve and thecheck valve to bleed back fluid from said tool to said reservoir wherebyfluid pressure is removed from the tool.

2. A control as set forth in claim 1 which further includes means forselectively energizing and deenergizing said pump.

3. In fluid-pressure-operated crimping apparatus including afluid-actuating crimping tool, a fluid reservoir, and means to supplyfluid under pressure from the reservoir through a fluid line to thecrimping tool for effecting a crimping action; a control having a firstfluid passage interconnected to said fluid line, said control includinga normally closed check valve in the passage adapted to open and supplyfluid to the tool when fluid under pressure is supplied from said supplymeans and to prevent return of fluid from the crimping tool through saidvalve, a second fluid passage communicating with the first passagedownstream from the check valve between the check valve and the tool andcommunicating with the first passage upstream from the check valvebetween the check valve and the means to supply fluid under pressurethereby bypassing the check valve, means actuated when the fluid.pressure in the first fluid passage reaches a preselected maximumpressure to prevent an increase in thefluid pressure in the tool abovethe preselected maximum pressure, an auxiliary valve in the bypasspassage, means biasing the auxiliary valve closed against apredetermined fluid pressure downstream from the check valve, theauxiliary valve being responsive to pressure downstream from thecheck'valve'to open when the downstream pressure exceeds thepredetermined pressure, the means biasing the auxilary valve closedautomatically reclosing the auxiliary valve when the fluid pressure inthe tool and downstream from the check valve falls below thepredetermined pressure whereby-the tool remains under substantially saidpredetermined fluid pressure after the pressure in the fluid line .fallsbelow the predetermined value, and means for selectively relieving thefluid pressure in the bypass passage between the auxiliary valve and thecheck valve to bleed back fluid from said tool to said reservoir wherebyfluid pressure is removed from the tool.

4. A control for a fluid-pressure-operated crimping tool adapted to beactuated by fluid under pressure from a supply source, a fluid lineinterconnecting said control and said supply source, said controlcomprising a body having a passage therethrough for flow of pressurizedfluid from the source to the tool, a first normally closed valve in thepassage in said body adapted to open for flow of fluid to the tool inresponse to the supplying of pressurized fluid to said passage, saidbody having a bleed communicating with the passage downstream from thevalve between the valve and the tool and communicating with the passageupstream from the valve between the valve and the source of fluidpressure for bleeding ofl pressurized fluid from said passage downstreamfrom said first valve, and a second valve in the bleed for controllingsaid bleed, means biasing the second valve closed against apredetermined value of fluid pressure downstream from the first valve,said second valve being opened when pressure downstream from said firstvalve exceeds the predetermined value, the biasing means automaticallyreclosing said second valve and said bleed when the fluid pressure inthe tool and downstream from the check valve falls below saidpredetermined value whereby said second valve holds pressure atsubstantially said predetermined value in said tool upon cessation ofsupply of fluid under pressure to said passage and upon venting ofpressure from said passage upstream from said first valve, said controlfurther including manually operable means for selectively opening saidsecond valve thereby permitting fluid in said tool and said bleed toreturn through said fluid line whereby fluid pressure is removed fromsaid tool.

5. A control as set forth in claim 4 in which said supply sourceincludes a reservoir and a pump, and said control further includes meansfor selectively energizing said pump.

6. Crimping apparatus comprising a fluidpressure-operated crimping toolincluding dies adapted when actuated to close upon and thereafter crimpa workpiece, a fluid reservoir, 21 fluid line, a pump for deliveringpressurized fluid from said reservoir to said line, and a controlinterconnected to said pump by said line and having a fluid passage forsupplying pressurized fluid to said tool and a check valve in saidpassage adapted to open for flow of pressurized fluid to said tool andto close upon cessation of delivery of pressurized fluid to saidpassage, said control further including a bleed communicating with thepassage downstream from the check valve between the check valve and thetool and communicating with the passage upstream from the check valvebetween the check valve and the line for bleeding pressure from the tooldownstream from the check valve, said bleed including a second valve,means biasing the second valve closed against a predetermined value ofpressure downstream from said check valve, the second valve being openedwhen said pressure downstream from said check valve exceeds saidpredetermined value, the biasing means automatically reclosing saidsecond valve and said bleed when the fluid pressure in the tool anddownstream from the check valve falls below said predetermined valuewhereby said second valve maintains the fluid pressure at said tool atsubstantially the predetermined value upon cessation of supply ofpressurized fluid from said supply source and upon venting of pressurefrom said passage upstream from the first valve, said control havingmeans for selectively actuating said pump whereby upon initial momentaryactuation of the pump said predetermined fluid pressure will be appliedto said tool to close said dies upon said workpiece and lightly grip itand upon subsequent pump actuation increased fluid pressure will beapplied to the tool to cause the dies to crimp said workpiece, and meansfor selectively opening said second valve to bleed back fluid from saidtool to said reservoir whereby the dies will reopen and release theworkpiece.

7. Crimping apparatus as set forth in claim 6 which further includesmeans actuated when the pressure in said line exceeds a preselectedmaximum value to permit fluid to return to the reservoir whereby whenthe crimping of the workpiece is completed the supply of pressurizedfluid to said tool will be discontinued and upon operation of saidselective actuation means to d'eactuate the pump the fluid pressure atsaid tool is reduced to said predetermined value and the dies willcontinue to grip said crimped workpiece.

8. Crimping apparatus as set forth in claim 7 wherein said pump is anelectrically actuated pump and said means for selectively actuating saidpump is an electric switch.

9. Crimping apparatus as set forth in claim 7 wherein said pump is apneumatically driven pump and said means for selectively actuating saidpump includes a pneumatic valve.

References Cited by the Examiner UNITED STATES PATENTS 1,706,309 3/ 1929Miller 6052 2,467,509 4/ 1949 Trautman 605 2 2,573,993 11/1951 Sedgwick6052 2,921,438 1/ 1960 Klingler 6052 SAMUEL LEVINE, Primary Examiner.

EDGAR W. GEOGHEGAN, Examiner.

1. A CONTROL FOR A FLUID-PRESSURE-OPERATED CRIMPING TOOL ADAPTED TO BEACTUATED BY FLUID UNDER PRESSURE FROM A SUPPLY SOURCE INCLUDING ARESERVOIR AND A PUMP, A FLUID LINE INTERCONNECTING SAID CONTROL AND SAIDSUPPLY SOURCE, SAID CONTROL COMPRISING A FIRST FLUID PASSAGE AND ANORMALLY CLOSED CHECK VALVE IN SAID PASSAGE ADAPTED TO OPEN AND SUPPLYFLUID TO SAID TOOL WHEN FLUID UNDER PRESSURE IS SUPPLIED FROM SAIDSOURCE, SAID CONTROL FURTHER INCLUDING A SECOND FLUID PASSAGE BYPASSINGTHE CHECK VALVE, AN AUXILIARY VALVE IN THE BYPASS PASSAGE, MEANS BIASINGTHE AUXILIARY VALVE CLOSED AGAINST A PREDETERMINED FLUID PRESSUREDOWNSTREAM FROM THE CHECK VALVE, THE AUXILIARY VALVE BEING ADAPTED TOOPEN WHEN THE PRESSURE IN THE TOOL AND DOWNSTREAM FROM THE CHECK VALVEEXCEEDS THE PREDETERMINED PRESSURE, THE MEANS BIASING THE AUXILIARYVALVE